one-pedal driving in B

[Blackgolf]

with my first EV e-GOLF for the a few days, I find out the one pedal driving in B mode can handle most situations, highway, local or sudden stop. I just use"gas" pedal to adjust both break and acceleration. if I need slow down a little bit, I just release gas pedal a little bit to create the corresponding drag I need. the more I release, the more drag it creates. if sudden stop required, just release the gas pedal more, even fully off the gas pedal. In this way, I only need brake pedal at the last moment of stop or emergency stop. Anyone know if this is the most fuel efficient way to drive? I do not like shift between D, D1,2,3 and B frequently, it is inconvenient IMO. well, for a long downhill coast, sure, using D1 or D2 is better for sure. thanks.

 

[srue]

It's no more or less efficient than using the brake pedal to initiate regenerative braking. B mode simply grants the accelerator some of that functionality. It comes down to personal preference. Some people like to coast, which is easier in D mode, but also possible in B. I, like you, prefer the feel of one-pedal driving, but ultimately it's just a preference. There is no inherent efficiency difference, though it may change how you drive, which could include a (likely small) difference.

 

[f1geek]

B should be less efficient than D for constant speed traveling (though I think B is more comfortable for local street driving since I have to brake often), because unless you have superior concentration, you will occasionally slow down by lifting and whenever you convert one form of energy (kinetic) to another form (chemical), you have entropic losses that just can't be avoided. How much do you lose to entropy? That depends on how often the car slows down thanks to your right foot. Enjoy the drive!

 

[Blackgolf]

how can you coast in D? you have to use brake to adjust speed which creates heating energy loss, less efficient. Unless you coast much earlier which upset people behind you.

It's no more or less efficient than using the brake pedal to initiate regenerative braking. B mode simply grants the accelerator some of that functionality. It comes down to personal preference. Some people like to coast, which is easier in D mode, but also possible in B. I, like you, prefer the feel of one-pedal driving, but ultimately it's just a preference. There is no inherent efficiency difference, though it may change how you drive, which could include a (likely small) difference.

 

[Blackgolf]

agree, it requires a steady foot. for a long highway travel, I would use ACC with B

B should be less efficient than D for constant speed traveling (though I think B is more comfortable for local street driving since I have to brake often), because unless you have superior concentration, you will occasionally slow down by lifting and whenever you convert one form of energy (kinetic) to another form (chemical), you have entropic losses that just can't be avoided. How much do you lose to entropy? That depends on how often the car slows down thanks to your right foot. Enjoy the drive!

 

[srue]

In D the brake pedal first slows the car with regenerative braking, not friction. If you know you need to slow over a long distance (approaching a speed limit change, for example) but have no traffic behind you, just lift off the pedal. I personally don't find it useful, but some people seem to find it very valuable. I'm glad we get the choice.

how can you coast in D? you have to use brake to adjust speed which creates heating energy loss, less efficient. Unless you coast much earlier which upset people behind you.

 

[Blackgolf]

thanks. good to hear that.

In D the brake pedal first slows the car with regenerative braking, not friction. If you know you need to slow over a long distance (approaching a speed limit change, for example) but have no traffic behind you, just lift off the pedal. I personally don't find it useful, but some people seem to find it very valuable. I'm glad we get the choice.

how can you coast in D? you have to use brake to adjust speed which creates heating energy loss, less efficient. Unless you coast much earlier which upset people behind you.

 

[JoulesThief]

You will absolutely drive anyone driving behind you nuts with driving in "B" mode. Every time you start to lift the throttle, your brake lights automatically come on. That's not the case in D D1, D2 and D3.

It's annoying as hell in stop and go traffic on the freeway.

You also develop poor driving habits, if you get into another vehicle that doesn't have a "B" mode while driving, causing you to expect the car to slow down immediately when you lift from the throttle, and it doesn't... causing you to possibly panic brake because the different to your e-Golf car doesn't behave as expected.

 

[Blackgolf]

Unlike D1,2 and 3, the drag created by B is adjustable, so B can replace D1,2,3. but not as convenient as D123 for a long downhill. B is perfect for stop & go traffic on the highway. I guess the brake light does not come up unless you completely off the gas pedal? I wish the brake light on/off is decided by either brake pedal or deceleration sensor.

You will absolutely drive anyone driving behind you nuts with driving in "B" mode. Every time you start to lift the throttle, your brake lights automatically come on. That's not the case in D D1, D2 and D3.

It's annoying as hell in stop and go traffic on the freeway.

You also develop poor driving habits, if you get into another vehicle that doesn't have a "B" mode while driving, causing you to expect the car to slow down immediately when you lift from the throttle, and it doesn't... causing you to possibly panic brake because the different to your e-Golf car doesn't behave as expected.

 

[f1geek]

Other than pressing the brake pedal, which, of course, actuates the brake lights, brake light actuation from regen braking is based on the rate of deceleration. D or D1 do not turn on the brake lights. In my experience, B, D2 and D3 actuate the brake lights (checked at night), but I suppose that may still depend on whether you are going uphill or downhill when you brake in those two modes. At least when I tested on relatively flat ground, I saw B, D2 and D3 actuate the brake lights.

 

[Blackgolf]

Alright, I did experiment at the flat road by putting the baking foil as reflector . see pictures link below.

Result :
1. In D1,2 and 3, brake light never switched on at any condition. It is ON only when press the brake pedal.
2. In B, brake light switched on ONLY when the foot completely off the gas pedal AND at higher speed. So when driving in B, brake light is OFF during deceleration unless gas pedal is completed released. This result matches what I expected.

https://drive.google.com/file/d/1UtbgdUzf0BOSf-VPfQvUxzgrD7BgCfS7/view?usp=sharing

https://drive.google.com/file/d/1WPww-kvkGf8sl1BMQ3jdE2Oaicfm74E1/view?usp=sharing

Other than pressing the brake pedal, which, of course, actuates the brake lights, brake light actuation from regen braking is based on the rate of deceleration. D or D1 do not turn on the brake lights. In my experience, B, D2 and D3 actuate the brake lights (checked at night), but I suppose that may still depend on whether you are going uphill or downhill when you brake in those two modes. At least when I tested on relatively flat ground, I saw B, D2 and D3 actuate the brake lights.

 

[f1geek]

In my testing I fully removed my foot very quickly. Again, brake light actuation is based on deceleration rate sensed by the car.